Sometimes, it is very difficult to know what kind of animal a particular species is. Different animals in the same class or order may appear very far apart from each other, even if they are closely related enough to be part of the same taxon.
After all, look at rabbits and humans. We are completely different in every way you can imagine. Humans are many times bigger than rabbits and we are not covered in fur like they are. We walk on two legs while they jump on four, and we have eyes in front of our heads while rabbit eyes are on the sides of their heads. Despite the many differences between our two species, humans and rabbits are classified as mammals.
So, what exactly qualifies as a species as a mammal, and how does this show the similarities between rabbits and other mammals such as humans? We’ll get to that in a moment, but first, we need to have a brief discussion of animal classification to make sure we speak the same language.
How Are Animals Classified?
Scientists have a system for classifying animals. This hierarchy contains several groups, each of which is known as a taxon. Each taxon contains many different animal species that are related in several major ways. As you move down the list, the similarities between species in the same taxon get greater, and the number of species in each taxon gets smaller. The hierarchical list of animal classifications is:
All animals belong to Kingdom Animalia, which is at the top of the hierarchy. Vertebrates, including humans and most of the animals you know, are part of the Phylum Chordata. Mammals are part of the Class Mammal, although there are many creatures in other classes. Other animal classes include Class Reptilia, Amphibia, Aves, and many more.
What Are Mammals?
Rabbits, along with humans, lions, seals, bears, squirrels, and many other vertebrates are mammals, which means they are part of the Class Mammal. But what exactly distinguishes mammals from reptiles, birds, or other classes of creatures?
Each class of animals has special characteristics that are shown by its members. In order for an animal to be assigned to any class, it must meet all the requirements of that class. According to Britannica, several very specific traits must be met to be considered a mammal.
For example, the creature must have hair, except in the case of whales where they only have hair during the fetal stage. In addition, mammalian offspring must receive nourishment from the milk produced by the mother’s mammary glands. If the females of a species do not have mammary glands, then they are not mammals.
Mammals also have a muscular diaphragm to keep the abdominal cavity separate from the heart and lungs, and only the left aortic arch survives. This is in contrast to other classes of animals, such as birds which have only a right aortic arch, or reptiles, amphibians, and fish, which all still have both aortic arches.
Lastly, mammals have red blood cells without a nucleus, and they are the only vertebrates with this trait. Other classes of animals all have red blood cells that contain a nucleus.
Are Rabbits a Mammal?
Now we have several criteria that we can use to determine whether a rabbit belongs to the Class Mammal or not. The first criterion, hair, is obvious. Everyone knows that rabbits are covered in fur.
What about the mammary glands? It is important for animals to be classified as mammals, and as it turns out, rabbits actually have an average of eight mammary glands, which is quite a lot to slaughter. Turns out, rabbits also have diaphragms, so they seem to be checking all the boxes for mammalian hoods.
What about red blood cells? Well, like all other mammals, rabbit red blood cells do not have a nucleus, which means they actually qualify for the Class Mammal. Rabbits are mammals.
Are Rabbits Rodents?
Rabbits are part of the Class Mammal, but in what order do they belong? They look like giant rats or chinchillas, does that mean they are rodents?
Rodents belong to the Order Rodentia. Rabbits, on the other hand, belong to the Order Leporidae, which includes hares and hares. However, as you can see, rabbits and hares are in a completely different order than rodents, so no, rabbits are not rodents.
While we don’t seem to have much in common with little bunnies, the similarities may go deeper than you think. While humans don’t grow fur coats, we do grow hair. Females of both species feed their young with milk which is produced in the mammary glands and has a diaphragm to separate the heart and lungs from the abdominal cavity. And if you examine the blood of rabbits microscopically, you will find that like all other mammals, their red blood cells do not have a nucleus, which binds them firmly to the Class Mammal.
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